Various types of portable shelters are known in which the shelter is permitted to be collapsed for storage when not in use. Examples of portable shelters include U.S. Pat. No. 6,349,732 to Cooper, U.S. Pat. No. 4,116,206 to Warner et al., U.S. Pat. No. 5,746,237 to Arnic and U.S. Pat. No. 4,425,929 to Von Mosshaim. In each instance the shelter generally comprises a plurality of support arches which are pivotally coupled at opposing free ends thereof for relative pivotal movement between a collapsed position in which the support arches are all positioned adjacent one another and a domed structure in which the support arches are angularly offset from one another to form a dome structure with a suitable cover spanning the arches. Typical prior art shelters have limited collapsibility as the arches, even when positioned adjacent one another, are still sufficiently larger to fully span the width of the assembled shelter that the collapsed shelter remains cumbersome for storage.
U.S. Pat. No. 5,842,495 to Egnew et al. discloses a shelter including a plurality of support arches pivotal relative one another in which each arch is hinged at an apex thereof to permit the arches to be folded in half to further collapse the shelter for storage. The support arches are pivotally supported on respective base members in a manner so that when the support arches are pivoted against one another for collapsing, the apexes of the arches lie in a common plane which is perpendicular to the desired direction of folding. Awkward manipulation of the hinges is thus required as the outermost support arch when folding at the apex must stretch across the combined width of all of the arches stacked against one another. In addition to the awkward manipulation of the hinges, the stacked arrangement of the apexes still has considerable bulk.